Moved by Science in Motion

The successful arrival of the European Space Agency’s Huygens atmospheric probe on the distant Saturnian moon of Titan in mid-January was a moving event. Many in the multinational contingent of scientists, engineers and administrators that had gathered at ESA’s control facility in Darmstadt, Germany had worked on the mission for a decade or more. Once it was clear that the probe was working as planned, a palpable euphoria — a compound of relief and pride — pervaded the proceedings. One of ESA’s high-ranking NASA visitors was Al Diaz, director of the agency’s new science organization, the Science Mission Directorate.

Although the Huygens part of Cassini-Huygens was designed and built in Europe and led by ESA, the mission was conducted in close collaboration with NASA. Huygens itself had been brought to Saturn by Cassini. The interview took place at ESA Headquarters in Darmstadt on January 15th, the day after Huygens’s pictures of smoggy Titan revealed an icy orange-tinged topography sculpted by liquid ethane rivers and lakes – a place of shorelines, creeks and fog that’s utterly alien, and yet also fascinatingly Earth-like in many respects.

Michael Benson (MB): Let’s talk about Huygens. The probe landed successfully on Saturn’s moon Titan yesterday, and you looked quite moved at the press conference. Tell me about your own personal feelings.

Al Diaz (AD): My reaction had less to do with the science – although I was moved by the science- than it did to the fact that there are so few opportunities to be involved in historic events. And here’s one where, as I looked around the room, I could identify a hundred people I’ve worked with in the past 25 years. You see something like this happen, and you recognize how much it’s meant to everybody that you’ve worked with, and it just is a moving thing.

MB: Do you see an increased future for European-NASA collaboration after this?

AD: Oh, absolutely.

You know, there’s always been collaboration between us. But this is one of the first times where there’s a major accomplishment where the Europeans can claim a first — where they were the leader and the US was the supporter. I think that will motivate them to press forward and take on some responsibilities that they might not have done in the past. We can now depend on them to lead some things that are technologically more challenging than they might have done ten years ago.

MB: To what extent is astrobiology a motor for what NASA’s doing? How much of this is a quest to find conditions that may now be suitable for life, or conditions that might be precursors for life?

AD: Up until a year ago, it was a motivator for some of our science. Now, it’s a principal motivator for almost everything that NASA does.

What happened a year ago was the articulation of a vision by the President — which has a very strong flavor in it that NASA is about the search for life, and understanding the origin and evolution of life in the universe. So I think astrobiology will now become a lot more dominant.

I’m pleased to see that, because it’s been through a bit of a hiatus. Astrobiology is a term that was coined maybe 8 or 9 years ago. Before that, biology in NASA had grown to a peak around the time of the Viking project (the robotic landings on Mars in 1976). So in the mid-seventies, there was a substantial presence of biology in NASA, but then it dissipated.

What’s happened now is that biology has broadened, in the sense that what was biology has become astrobiology. It’s spread to earth science as well as biological and physical research, which was principally associated with human activity. I anticipate that over the course of the next decade, astrobiology will grow, largely driven by the search for life on Mars.

"The search for life takes a lot more competent kinds of payloads and instruments than we can accommodate in this era where we’re trying to get back onto Mars."–Al DiazCredit:ESA

MB: Do you think the reason that the emphasis on astrobiology waned after Viking was because there wasn’t any positive sign of life resulting from those two landers? And so would it be possible to say that the reason the current two Mars rovers don’t have any dedicated experiments to try to discover if there’s biological activity – although they are looking for water – would be because there was a fear in NASA that if they came up short, like the Vikings, then that could cut public interest in Mars exploration?

AD: No, I don’t think there was that motivation. The search for life takes a lot more competent kinds of payloads and instruments than we can accommodate in this era where we’re trying to get back onto Mars. I think the past 20 years were an effort to recover some capability to land on Mars. We’ve done it quicker, better, cheaper, and we’ve done it now, finally, in a much more painstaking and traditional mode. It won’t be until the next lander payload, which will not be the scout, but the next…

MB: The big heavy rover? With the biological lab on it.

AD: Right, exactly. With the chemical lab on it, that will ultimately, I think, become, in its successor forms, a biological laboratory. Then we will be where we wanted to be immediately after Viking. We wanted to take the lander, and put wheels on it, and roll it around the planet. We’re now back on the planet. When we land the Mars Science Lander, we will be ahead of where we were. We’ll have a competent scientific laboratory on wheels.

MB: Would it be accurate to say that the Mars Science Lander is probably the most exciting single robotic mission on the boards right now?

AD: It’s two and a half tons. It’s big. It’s another generation beyond the Opportunity and Spirit rovers.

MB: The two leading contenders for potential hosts for extraterrestrial life are Mars and Europa. Europa almost certainly has a vast ocean with a surface ice crust. Rick Greenberg, who has a team at the University of Arizona, at the Lunar and Planetary Science lab, just released a book called "Europa: Ocean Moon," where he makes a persuasive case that the ice shell is comparatively thin, and that there’s substantial interaction between the ocean and the surface because of all of the cracks in the ice. It means that surface chemistry can get into the water, creating conditions for life. So I’m wondering why it is that NASA doesn’t have a mission on the boards right now to go to Europa.

AD: We do. It’s called the Jupiter Icy Moons Orbiter. The Europa mission is the highest priority in the outer planets, as outlined by the decadal plan from the National Academy of Sciences. We recognize Europa as being the "sweet spot" of the outer planets, if you will. So we’re anxious to do it. Right now, we’re focusing on JIMO as the solution.